SEOUL, Nov. 22 (Yonhap) -- Seoul blasted Tokyo Thursday over its reported move to name peaks on South Korea's easternmost islets of Dokdo, saying it would amount to a "serious violation" of its territorial sovereignty.

Tokyo has long laid claim to the islets, which lie closer to South Korea in the body of water dividing the Korean Peninsula and Japan, often leading to diplomatic tensions between the neighboring countries.

According to Japan's Kyodo News Service, the Japanese government decided earlier in the day to consider naming the peaks on Dokdo, which could be listed on maps created by the Geospatial Information Authority of Japan.

"If the Japanese media report is true, it would be a serious violation of our territorial sovereignty," an official at Seoul's foreign ministry said, asking not to be identified. "We won't tolerate it."

Seoul will also protest the move to the Japanese government and demand it be canceled if the report turns out to be true, the official added.

The move comes after the Seoul government renamed the peaks last month in an apparent bid to bolster its sovereignty over the territory, which it effectively controls. The peaks are now called Usanbong and Daehanbong.

Japan's territorial claim to Dokdo is viewed by Koreans as a sign Tokyo has not fully repented for its imperialist past.

South Korea reclaimed sovereignty over its territory when it regained independence from Japan's 36-year colonial rule in 1945.